A comprehensive study of ondansetron hydrochloride drug as a green corrosion inhibitor for mild steel in 1Â M HCl medium

The inhibiting action against the corrosion of mild steel by ondansetron hydrochloride (ODSH) drug was studied, using various studies such as weight loss, electrochemical impedance spectroscopy, potentiodynamic polarization measurement, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), FT-IR spectroscopy and reactivity of molecule is studied using quantum chemical calculation. The result shows that ondansetron hydrochloride (ODSH) gives better inhibition on mild steel. The value of activation energy (Ea) and various thermodynamic parameters such as adsorption equilibrium constant (Kads), free energy of adsorption (ΔG0ads), adsorption enthalpy (ΔHads) and adsorption entropy (ΔSads) was calculated and discussed. The adsorption of ODSH on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurement reveals that ODSH acts as a mixed-type inhibitor. Electrochemical impedance spectroscopy (EIS) spectra exhibit one capacitive loop indicating that, the corrosion reaction is controlled by charge transfer process. SEM, EDX, AFM, FT-IR conforms to the protective film formation. Quantum chemical calculation was calculated and discussed, and it supports the results.